The value of a program is its ability to pursue an integrated scientific theme and integrate diverse investigators. An equal number of individuals projects (R01's) may result in as such information but neither it nor the individual's PI's will share a direction. The core scientific concept of a program project provides the most important integration of a project. Intercommunication and the sharing of technology throughout the project is a second important source of integration. An instrumentation core becomes central to a program project by providing the shared technology, nurturing that technology, and supply efficient means of communication. Over the last two funding cycles for our project the Instrumentation Core has evolved to focus on the integration of the program project. Our aims remain much the same, but our emphasis has shifted away from the construction of electronic circuits and the development of biological measurement instrument to the development and maintenance of computer systems/networks and the integration of laboratory and ambulatory equipment with these systems/networks. We have increasingly recognized that it is more cost-effective to contract for special purpose equipment design and equipment modification. As our needs in this area have decreased, it has not been economical to retain an employee specializing in circuit design and construction.